In the chapter Getting Mouse Events, we’re supposed to override three methods of NSResponder: mouseDown(), mouseDragged() and mouseUp().
Starting with Swift 2, the function println() is not available and has to be replaced by print(). But when I made these changes, I got several warnings from Xcode telling me to fix my code. According to Xcode, the print() function should be prefixed by the keyword Swift.
You will also find an errata document with some of the errors of the book (but it’s not even close to being complete).
You’ll have to search through this forum to find answers beyond that.